ci(docs-linting):support complex documentation structures

[edro15]

👉 Please ensure your pull request (PR) adheres to our Contribution Guidelines 👈

Pull Request Checklist

Please check if your PR fulfills the following requirements:

• Testing of all the changes has been performed (for bug fixes / features)
• The docs/readme.md has been reviewed and updated if needed (for bug fixes / features)
• Provide release notes as part of the PR submission which describe high level points about the changes
• Verify all checks are passing
• Do NOT use the main branch of the forked repo. Create separate feature branch for raising the PR

Pull Request Type

Please check the type of change your PR introduces:

• Bugfix
• Feature
• Code style update (formatting, renaming)
• Refactoring (no functional changes, no api changes)
• Documentation
• Other (please describe): Workflow enhancement

Security Considerations (REQUIRED)

• If you are adding an integration with 3rd party system
  • Please document in the docs/readme.md all methods (eg, OAuth) used to authenticate
    with the service that the add-on is integrating with

Release Notes (REQUIRED)

• Edited the docs linting pipeline to support more complex documentation structures such as done in the pexip add-on for Splunk